Hear hear for the gist of the article, and for the very nice examples.
I think that focal length used really depends a lot on the terrain and subject - some "enclosed" subjects may require distinctly wide angle (or a medium-wide or a normal lens with panorama), for example, the mini-slot canyons in karst limestone territory, or landscapes where the framing by near objects is important, or skyscapes. I use 35 or 40mm the most, then short tele, then 21mm (the limestone formations; skyscapes) for local (Missouri) nature landscapes.
A small point - some of the photos would be regarded by some as "wildlife" photos or reportage and not "landscape" photos. Also, 35mm might be regarded by "old-timers" (from film era when 50-55mm was considered "normal" length) as "slightly wide". My first lens was a Mamiya-Sekor 55mm f/1.4, from the very short era when Mamiya made 135 format cameras as well as their MF line.